Technical Field
The present invention relates to a radionuclide adsorbent, a method of producing a radionuclide adsorbent and a production apparatus thereof, and more particularly to a radionuclide adsorbent suitable for adsorption of radioactive cesium and radioactive strontium, a method of producing radionuclide adsorbent and a production apparatus thereof.
Background Art
As one of treatment methods of a radioactive waste liquid including radionuclides generated in nuclear power facilities, there is a treatment method of adsorbing and removing radionuclides by an inorganic adsorbent and an ion exchange resin.
The radioactive cesium and radioactive strontium among the radionuclides included in the radioactive waste liquid become a heat source and a radiation source, so that it is preferable to separate them from the radioactive waste liquid.
Since the radioactive cesium and radioactive strontium included in the radioactive waste liquid are different from each other in the chemical property, there is a method of separating the radioactive cesium and radioactive strontium using different adsorbents, as described in Japanese Patent Laid-open No. 2007-271306. Further, as an adsorbent of separating the radioactive cesium included in the radioactive waste liquid by adsorption, for example, a Prussian blue metallic complex described in Japanese Patent Laid-open No. 2011-200856 and calix described in Japanese Patent 4879869 are used. Further, as an adsorbent of adsorbing the radioactive strontium, for example, there is manganese dioxide described in Japanese Patent Laid-Open No. 4(1992)-86599. Furthermore, the adsorbent proposed in Oji et al., WM2012 Conference, Feb. 26-Mar. 1, 2012, Phoenix, Ariz., USA, 12092 (2012) is granular crystalline silicotitanate (CST) and the CST can adsorb both of cesium and strontium. If this adsorbent is used, both of radioactive cesium and radioactive strontium can be separated and removed from the radioactive waste liquid.
May Nyman, et al., “Characterization of UOP INOSIV IE-911”, SANDIA REPORT, SAND2001-0999, Printed June 2001, Sandia National Laboratories describes that when a radioactive waste liquid including Cs is supplied to a column with CST filled, the column is clogged with Zr, Nb and a treatment efficiency of the radioactive waste liquid including Cs is reduced, and in order to prevent a reduction in the treatment efficiency, the CST is treated with a sodium hydroxide solution beforehand to remove soluble Zr, Nb, and Si.